Spectroscopic analysis provides information about the identity, structure, and concentration of the chemical species of a given sample using the detected energy change of an atom or molecule through either the emission or absorption of a photon. Absorption spectroscopy measures the net absorption of incident radiation throughout a chosen wavelength range. Radiation passing through a sample is attenuated depending upon the path length traveled by the radiation, the strength and concentration of absorbing species present and scattering losses. Unique spectral fingerprints arise from the absorption of photons of light at discrete (resonant) energies, signifying known electronic, vibrational and/or rotational energetic transitions. A plot of light absorbance or transmission versus wavelength for a given sample is used to map out the spectral fingerprints for species identification.
In general for absorption spectroscopy, an arrangement of light sources, fiber optics, mirrors, collimating lens and spectrometers are used to direct light through a given sample or interaction region, to collect the light emerging from the sample and to analyze the collected light. A given absorption spectroscopy system is sensitive to the sample and environment studied. In general, however, absorption spectroscopy systems are not constructed for use in hazardous environments where the systems or probes would experience elevated temperatures and pressures.
A known arrangement for use in hostile environments is a Raman fiber optic probe assembly. In this case, the hostile environment is an autoclave, and the probe forms a dry well assembly. The probe is positioned inside a shell and supported by a hanger pipe. The arrangement of the probe makes it suitable for pressures up to 2000 psi and temperatures up to 600° F. However, the probe is isolated from the hazardous environment and requires sturdy structures to provide this physical isolation.
Other arrangements of apparati for spectroscopic analysis in hazardous environments are disclosed in the related art. However, the arrangements are application specific, and no device is arranged for measuring the post-detonation combustion cloud of energetic materials, and in particular for providing a probe or gauge that can be placed within the detonation cloud to analyze the species in the cloud in particular over the very brief time period associated with a detonation event.